Step 8: Make the blob button

Step 9: Finished product

Heres the finished light. smaller than the one you can buy. I think it would be possible to use two LED's to make it brighter, or use a larger LED (5m...

Build this handy little torch that can be kept in spaces smaller than a matchbox and be left feeling all dandy. BEWARE this is not a project for the unpatient. it may look like a small project but in fact it will take longer to build than you think.

Step 2: Pry open battery clip

pry open and remove both wires including the metal tabs that held them

Step 3: Drill hole in the middle of the top half of the battery clip

Step 4: Solder the resistor to positive terminal of the battery clip like shown in the photo

Step 5: Solder on LED

Note: solder the positive lead of the LED to the resistor (the LED and resistor leads have to be cut off as short as possible to save space as there isnt much left in the battery clip) and bend the negative lead out in the direction of the opening where the wires used to go out of. DO NOT CUT THE NEGATIVE LEAD OFF.

Step 6: Test the circuit

Test the circuit by pushing the battery clip onto the 9V battery and pushing the negative lead of the LED onto the negative terminal of the battery.

You may also want to strengthen the negative lead of the LED so that the wire doesnt change shape when you push it, otherwise the switch will deform and stop working

Step 7: Close the battery clip if it works

If the LED glows when you tested the circuit you are ready for closing the batery clip. It might take some squeezing to get it all in the right place and snapped shut.

Note: the negative lead of the LED has to be threaded through the hole in the top half of the battery clip before closing it

Step 8: Make the blob button

Cut the wires extending out of the battery clip to about 7mm. Put a blob of hot glue on it. Once the hot glue has hardened colour it in with black vivid. Theres the dandy light finished

Step 9: Finished product

Heres the finished light. smaller than the one you can buy. I think it would be possible to use two LED's to make it brighter, or use a larger LED (5mm). I believe the light should last about 8hrs or more. after all the LED only draws 20mA of current which will take a long time to drain the battery.

I've been told that if you wire it in series it'll still only use 20ma but wiring them in parallel it'll use 60. but since you have 9v to play with it would be smarter to use 3 white leds with no resistor. most white leds are 3v.

-------------------------------------------------------- "May the good belong to all the people in the world. May the rulers go by the path of justice. May the best of men and their source always prove to be a blessing. May all the world rejoice in happiness. May rain come in time and plentifulness be on Earth. May this world be free from suffering and the noble ones be free from fears" ---- Vedic blessing

indeed a great beautiful project, compliments, has estimated it the maximum, I adores the minimalistic inventions, has realized instructable a much similar one to yours, that mine it is a portable usb charger a not torch, but the small torch is however much pretty one, very good!

Nice Instructable. I especially like your drawing in step seven, very detailed. I wish more people could learn to draw like you rather than a puddle of color made in paint that "illustrates" how to build a car. :)

This circuit is a LED and a resistor in series, lets say you have an high intensity LED, 3.4V 20mA. the resitor would have to have a voltage drop of (9-3.4) 5.6V, we then use ohms law to calculate the resistance.

R=V/IR=5.6/0.02 0.02= current through series circuitR=280ohm

If you want a brighter light just decrease the resistance a bit to that of your calculated value, generally this wont harm or shorten the life of the LED as the stated value for max current is usually lower than tollerant

for the cellphone battery emergency light..you could build some form of "clip harness" type deal that the cellphone battery could fit into with the led/resistor combo could be built into...so you could keep it in your bag...and in an emergency you just pop the battery out of your phone and stick it in the clip deal...thus making it work for the light...but you'd also still be able to stick the battery back into your phone for charging it..

This step is a little harder than it seems. I've ruined two of the battery clips lower halves by trying to pry off the bottom. It seems like it is really attached on there well. Anyone have any tips on prying off the lower half.

I didn't quite answer your question yet. well the higher the current used by your circuit (resistor and LED in series) the shorter it will last. So get a high efficiency LED that will lengthen how long the battery lasts

Yup. First you have to figure out how many milliamps per hour your battery supplies. unfortunately this is not written on most normal batteries. But fortunately most rechargable 9V batteries are similar to non rechargable 9V batteries. Most rechargeable ones supply 150mAhr. Soooo. all you have to do is measure the current leaving the battery when its turned on and divide 150 by that number. (make sure you always work in milliamps). and that gives you your answer in hours. Well anyway thats how i think its done

I also remember seeing a commercial version of this with two different light settings. I bet it would be difficult but not impossible to do on your own. This is a rly great money saving project. I will attempt it eventually.

Yeah for this you could use different types of batteries to make the light smaller. I guess the cool thing is that large batteries like 9V and AA, AAA batteries can supply alot of current and therefore the LED will go for ages. but since batteries are getting smaller and last longer it would be very cool to use something like a cellphone battery. But you have to remember that the point of this torch is so that you can put it in a wallet or some emergency pack and buy the battery for it later when you need it. otherwise you might aswell by a LED keyring torch

This and the Tic-Tac light have given me some ideas. To get smaller/simpler, consider using a 3.7v Lithium ion cell from a small digital camera. My Pentax Optio uses a battery (D-L 18, and NP-40) that I was able to buy for $8.00. That is readily available via Ebay or Amazon third tier sellers for cheap. These wouldn't require a resistor either, but would require some ingenuity to attach the bulb/switch to the pack. I'd recommend using whatever you have a charger for. There should be many cellphone battery possibilities as well. Correct me if I'm wrong, but you should be able to connect more bulbs in parallel and get a brighter light.

I used a small LED to make it easier to put it all together. Of course you could use a 25mm LED but you might have to glue the LED on top of the battery clip because it will not fit into the clip. The LED i used was a normal 1.5-2 V LED that requires a resistor in order to run without blowing up. If 9V LED's are available that would make the job a hell of a lot easier but maybe more expensive. When i started the project i was thinking of using a flexible/soft LED snap. I would have done all the wiring like in the one above and then covered the whole thing in hot glue to wathever shape i wanted and then spray painted it. I think it would look quite cool

I used a small LED to make it easier to put it all together. Of course you could use a 25mm LED but you might have to glue the LED on top of the battery clip because it will not fit into the clip. The LED i used was a normal 1.5-2 V LED that requires a resistor in order to run without blowing up. If 9V LED's are available that would make the job a hell of a lot easier but maybe more expensive. When i started the project i was thinking of using a flexible/soft LED snap. I would have done all the wiring like in the one above and then covered the whole thing in hot glue to wathever shape i wanted and then spray painted it. I think it would look quite cool

I used a small LED to make it easier to put it all together. Of course you could use a 25mm LED but you might have to glue the LED on top of the battery clip because it will not fit into the clip. The LED i used was a normal 1.5-2 V LED that requires a resistor in order to run without blowing up. If 9V LED's are available that would make the job a hell of a lot easier but maybe more expensive. When i started the project i was thinking of using a flexible/soft LED snap. I would have done all the wiring like in the one above and then covered the whole thing in hot glue to wathever shape i wanted and then spray painted it. I think it would look quite cool

There is just one problem with glow in the dark paint. the LED will not shine much light to the side as most LED's are made to focus. But maybe a little paint just around the LED would work. Thanks for the cool idea